Often coated substrates are formed from multiple components. Take for example, aerospace applications. Aircraft often will have skins or outer surfaces which are attached to the structural support members via fasteners, such as rivets, screws or the like. In this situation, fasteners which are suitably secured for the fasteners primary purpose, may impact the final appearance of a subsequently applied coating. For example, a slightly gapped fastener-head, which is capable of performing the fastener's primary purpose, may nonetheless affect the overall finish of a coating which covers the fastener and material forming the outer skin. The coating may experience “paint wicks” or other defects which may impact the performance of the coating system or may merely be visually unappealing. For instance, an applied coating may enter a gapped space at the fastener/outer surface interface. While the coating may be treated to correct the visually unappealing area, these procedures are typically time consuming and may require skilled personnel attention.
Contact evaluation methodologies, such as the use of feeler gauges, are time consuming and may be used intermittently as a spot check on a representative number of fastener. Contact evaluation is time consuming as the gauge is placed in contact between the fastener and the member being secured by the fastener.